Corey Seager was the popular draft comp. Seems like a reasonable ceiling, although Colson might have better OBP numbers than Seager. Top 5 MLB SS is definitely possible at this point.
Floor? Idk. He COULD flame out at AA, I suppose. Not sure who a good name to attach to Colson for a floor. I guess the floor profile for him would be an average MLB defensive shortstop who can draw walks but never develops much power.